Digital control of on-chip magnetic particle assay

ABSTRACT

An assay system and method for use in the field of chemical testing is disclosed. The assay system can be used for filtering whole blood for testing on an integrated circuit containing digital control functionality.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/456,049, filed Mar. 10, 2017 (now U.S. Pat. No. 10,794,902),which is a divisional of U.S. patent application Ser. No. 14/942,903,filed Nov. 16, 2015, which is a continuation of PCT InternationalApplication No. PCT/US2014/033607, filed Apr. 10, 2014, which claimspriority to U.S. Provisional Application No. 61/825,464, filed May 20,2013; and U.S. Provisional Application No. 61/891,319, filed Oct. 15,2013, each of which are incorporated herein by reference in theirentireties.

BACKGROUND 1. Technical field

An assay system and method for use in the field of chemical testing isdisclosed. More particularly, the assay system can be used for filteringwhole blood for testing on an integrated circuit containing digitalcontrol functionality.

2. Summary of the Related Art

Point-of-Care (POC) diagnostic medical devices facilitate early stagedetection of diseases, enable more individually tailored therapies, andallow doctors to follow up with patients more easily to see ifprescribed treatments are working. To ensure widespread adoption, thesetools must be accurate, easy to use by untrained individuals, andinexpensive to produce and distribute. Immuno-Assay (IA) applicationsare particularly well-suited for the POC since a wide range ofconditions, from cardiovascular disease to cancer to communicableinfections, can be identified from soluble protein bio-markers. Thedetection and quantitation of these bio-markers from raw samples such aswhole blood often involves labeling the target protein using fluorescentor phosphorescent molecules, enzymes, quantum dots, metal particles ormagnetic particles. For high sensitivity applications, the labelsspecifically bound to the target analytes must be distinguished from theunbound ones that contribute to background noise. By combining bothlabel separation and detection in a low cost, easy to use format, theImmuno-Chromatographic Test (ICT) achieves stand-alone operation, i.e.the ability to perform an assay without necessitating an electronicreader or an external sample preparation system. Stand-alone operationis an often overlooked attribute, but one that is key to the popularityof ICTs, achieved despite other drawbacks such as low biochemicalsensitivity, user interpretation, inaccurate quantitation, timingrequirements, and awkward multiplexing.

The use of magnetic particle labeling is ideal for POC applications;magnetic particles can be individually detected, so sub-pico molarsensitivities can be achieved without signal amplification steps thatcan take up to an hour as in case of enzymatic labeling. Also, bymicro-arraying the sensing area sensing areas onto which the particlesbind, multiplexed operation can be achieved at low cost. The use ofmagnetic particles can reduce incubation times, since they can bind tothe target analytes with solution-phase kinetics due to their highsurface area to volume ratio. Furthermore, the ability to pull themagnetic particles out of solution magnetically and gravitationallyovercomes the slow diffusion processes that plague most high sensitivityprotocols. The signals from magnetic particles can be stable over time,insensitive to changes in temperature or chemistries and detected inopaque or translucent solutions like whole blood or plasma. Thebiological magnetic background signal can be low, so high assaysensitivity can be achieved with minimal sample preparation. Mostimportantly, the use of magnetic particles as assay labels can permitstand-alone device operation, since these particles can be bothmanipulated and detected electromagnetically.

“Magnetic particles” are nano-meter or mico-meter sized particles thatdisplay magnetic, diamagnetic, ferromagnetic, ferrimagnetic,paramagnetic, super-paramagnetic or antiferromagnetic behavior.“Magnetic particles” can refer to individual particles or largeraggregates of particles such as magnetic beads.

Magnetic particle sensors are sensor embedded in an integrated circuitthat can detect magnetic particles. Examples include optical sensors,magnetic sensors, capacitive sensors, inductive sensors, pressuresensors.

ICTs in which magnetic particles are used as the assay labels are animprovement to conventional ICTs since the detection of the particles isnot limited to the surface of the strip, but can be performed throughoutthe volume of the strip, resulting in higher sensitivities and improvedquantitative accuracy. However, volumetric detection of magneticparticles cannot be readily integrated in a stand-alone device, so theseimplementations require an external device to measure the volumemagnetization in the strip.

One alternative for integration into a stand-alone assay system is touse magnetic particles that bind to the target analytes in solutionbefore sedimenting via gravity or magnetic force to sensing areas wherethe specifically bound particles can be detected. A bio-functionalizedIC can be used to detect the specifically bound particles. However, mostIC-based immuno-assay implementations reported to date cannot operatestand-alone since they require either off-chip components for particledetection, or micro-fluidic actuation for particle manipulation andsample preparation. Other implementations simply cannot reach the coststructures necessary to compete in the current marketplace.

For POC application, it is desirable that the sample preparation berapid since the assay is limited to 10-15 minutes. In addition, toobviate the need for refrigeration equipment and to facilitate storageand distribution, a dry sample preparation system is desired. It is alsodesirable to have a sample preparation system that receives smallunprocessed samples from patients. The average hanging drop of bloodfrom a finger stick yields approximately 150 of fluid. For more fluid, acomplicated venu-puncture can be necessary. Moreover, the samplepreparation system must be low-cost since biological contaminationconcerns dictate that all material in contact with biological samples bediscarded. It is also desirable that the sample preparation system beamenable to multiplexed operation.

BRIEF SUMMARY OF THE INVENTION

A sample preparation system that can fulfill the requirements for speed,cost, and performance described above is disclosed.

A porous material like a membrane filter can obviate the need forcentrifugation or complicated micro-fluidic sample preparation. Sincethe membrane filters are compact and inexpensive, system cost isreduced, enabling stand-alone POC operation. Furthermore, the membranescan separate the plasma from the whole blood cells without additionalsupport in under 30 seconds. Incubation of the filtrate withfunctionalized magnetic particles can achieve solution phase kineticsfor rapid operation with sub pico-molar sensitivities. The use of an ICto perform the detection of the magnetic particles enables low cost,stand-alone operation. Therefore, the combination of a filter,capillary, magnetic particles and an IC can result in a stand-alone,accurate, multiplexed platform with the form factor of a thumb-drive.The size of the entire system excluding a battery and display can bereduced to under 1 cm3.

The assay system can be used for immuno-as says. The assay system can beused for nucleic acid, small molecule and inorganic molecule testing, orcombinations thereof.

A sample preparation system comprising a membrane filter and a capillarychannel configured to deliver magnetic particles to the exposed surfaceof an integrated circuit (IC) that manipulates and detects the particlesis disclosed. The large particulate matter in the sample, such as wholeblood cells, can be trapped on top or in the membrane, while the aqueoussample containing the target analytes traverses the membrane into theinlet of the capillary, where the magnetic particles can re-suspend andbind to the target analytes in the filtrate. The filtrate with there-suspended magnetic particles can flow through the capillary and ontothe sensing areas on the surface of the IC as a result of capillaryaction.

Magnetic particles bound to a target analyte can bind strongly throughspecific chemical interactions to the functionalized sensing areas onthe surface of the IC. The number of magnetic particles specificallybound to the surface of the IC is representative of the concentration ofthe target analyte in the biological sample presented.

The surface of the IC can contain one or more sensing areas. The sensingareas correspond to the areas on the surface of the chip in whichparticle sensors can detect specifically bound particles. The particlesensors can be embedded in the IC. Particle sensors can be placedoutside of the sensing areas to detect the non-specifically boundparticles removed from the sensing areas for an accurate count of thetotal number of magnetic particles.

The IC can contain one or more magnetic force generators to manipulatethe non-specifically bound magnetic particles on the sensing areas.These magnetic forces can be used to attract the magnetic beads to thesensing areas and to remove the non-specifically bound magneticparticles from the sensing areas. The system can have two or morecapillaries, for example where the inlet of a delivery capillary isplaced directly below the filter and delivers the filtrate into asedimentation capillary which is placed vertically directly above thesensing area. The dried magnetic particles can be placed at the top ofthe sedimentation capillary. From the top of the sedimentary capillary,the dried magnetic particles can sediment to the sensing area once thefiltrate reaches them. The length of time of the assay can be determinedby the height of the sedimentation capillary.

The assay system may be configured to take whole or previously filteredblood, urine, tear, sputum, fecal, oral, nasal samples or otherbiological or non-biological aqueous samples.

Chemicals, such as, but not limited to: aptamers, oligonucloetides,proteins, agents to prevent clotting, target analytes for internalcalibration curves, bindive catalytic agents, magnetic particles, orcombinations thereof may be dried in the membrane filter assembly alongthe shaft of the capillary or on the surface of the IC and can bere-solubilized by the blood plasma but remain bound to the surface uponwhich they were dried.

The assay system can contain user interface controls to simplify user.The fully dry assay system can calibrate background signal and thenative target signal. The assay system may invalidate the results ifcertain use-case conditions are not met.

The assay system may transmit the results to a secondary mobile devicefor storage and analysis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional side view of a variation of the assay system10 that includes a sample preparation and delivery module (SPDM) 8, alight source 2, an integrated circuit 12 (IC), a printed circuit board(PCB) 9, a display 1, and a casing 11.

FIG. 2 is a cross sectional side view of a variation of the assay system10 as the aqueous sample 5 is filtered and wicked via capillary actionthrough a delivery capillary 14 into the surface capillary 15 and onto asurface 7 of the integrated circuit 12.

FIG. 3 is a cross sectional side view of a variation of the assay system10 showing the aqueous sample 5 in the process of wicking up thesedimentation capillary 13 due to capillary action. Once the aqueoussample 5 reaches the top of the sedimentation capillary 13, the aqueoussample 5 can re-hydrate a reagent sphere 3, releasing the particles 4 tosediment onto the surface 7 of the IC 12.

FIG. 4A and 4B are top and cross sectional side views, respectively, ofa variation of the IC 12 containing a magnetic separation fieldgenerator implemented with separation conductors.

FIG. 4C is a cross-sectional view that presents the scenario from FIG.4A and 4B after non-specifically bound magnetic particle 25 is attractedto a separation conductor 23.

FIG. 5A is a cross sectional side view of cuvette 30 storing the drysphere 3.

FIG. 5B is a cross sectional side view of cuvette 30 after the aqueoussample 5 dissolved the dried sphere 3 and released the particles 4.

FIG. 6 is a cross sectional side view of a cuvette with tapered sidewalls 40.

FIG. 7 is a cross sectional side view of a cuvette 30 with a cover 50 tocontain the dried sphere 3 in the cuvette.

FIG. 8 is a cross sectional side view of the surface capillary 15constructed from double sided tape 60.

FIG. 9 is a top view of the surface of the integrated circuit 12 withthe double sided tape 60 mounted on it. The sensing area 21 can besituated under the sedimentation capillary, while the active area 71 canbe situated along the length of the surface capillary.

FIG. 10 shows a cross of the system with a delivery capillary 14 leadingto two surface capillaries 15 and 62, which lead to two sedimentationcapillaries 13 and 63, respectively, for controls or multiplexedoperation.

FIG. 11 shows a cross section of the integrated circuit 12 mounted ontothe PCB 9 and electrically connected via a wirebond 81. The wirebond 81can be hermetically sealed by encapsulant 80.

FIG. 12 shows a cross section of the integrated circuit 12 mounted ontothe PCB 9 and electrically connected by way of one or morethrough-silicon vias 82.

FIG. 13 shows the top view of the integrated circuit surface 7 with onedigitally addressable separation conductor 90 per sensor.

FIG. 14 shows the top view of the integrated circuit surface 7 with onedigitally addressable separation conductor 90 and one digitallyaddressable concentration conductor 92 per sensor

FIG. 15 shows the cross section of the sedimentation capillary 13 with anotch 100 to retain the dried sphere 3 in the sedimentation capillary 3.

FIG. 16 shows the cross sectional view of the delivery capillary 14, thesurface capillary 15 and the sedimentation capillary 13 and passiveunidirectional valve that prevent the suck-back of aqueous sample fromthe sedimentation capillary to the filter.

FIG. 17A is a cross-sectional side view of a flow stop 120 placed abovethe dry sphere 3, before the aqueous sample 5 has dissolved the drysphere 3.

FIG. 17B is a cross sectional side view of a flow stop 120 that hashermetically sealed the top of the sedimentation capillary 13 after theaqueous sample 5 has dissolved the dry sphere 3 and released theparticles 4.

DETAILED DESCRIPTION

Biosensors that use non-magnetic or magnetic particle labeling toperform assays are disclosed. A particle can serve as an aid, or label,in detecting the presence or absence of a target analyte if the particleis attached to a chemical entity that reacts with the analyte, oranalyte analogue, or analyte by-product. The reaction can beimmunological, nucleic acid based, covalent, ionic, hydrogen bonding,van der Waals and other chemical reaction phenomena capable of promotingor inhibiting the labeled particle from binding to a surface.

Particles may be any spherical or arbitrarily shaped localized objects,from several nanometers to tens of microns in diameter, that modulateincoming light (e.g., reflect the light, refract the light, block orabsorb the light, increase or decrease the intensity of the light,change the wavelength or spectral composition of the light). Particlesmay also be magnetic. Magnetic particles display diamagnetic,ferromagnetic, ferrimagnetic, paramagnetic, superparamagnetic, orantiferromagnetic behavior. Magnetic particles may include individualnanometer-sized particles of magnetic material (often referred to asmagnetic nanoparticles or magnetizable nanoparticles) or largeraggregates of such magnetic nanoparticles to form an essentiallyspherical bead (often referred to as magnetic beads, magnetizablebeads). Magnetic particles may be covered with or encapsulated by anon-magnetic material, such as a polymer, glass, ceramic, or any othernon-magnetic material, that may be coated with biological or chemicalmolecules that react specifically to a target analyte. A non-magneticmaterial refers to any material that displays no magnetic properties ordisplays magnetic properties that are much smaller in magnitude (e.g.,less than 0.001%) than the corresponding properties of the magneticmaterial in magnetic particles. Magnetic particles may be from severalnanometers to tens of microns in diameter.

FIG. 1 shows an assay system 10 that includes a sample preparation anddelivery module (SPDM) 8, a light source 2, an integrated circuit (IC)12, a printed circuit board (PCB) 9, a display 1, and a casing 11. Theassay system 10 may be configured to perform a biological and/orchemical assay on an aqueous sample 5 by introducing, detecting, and/orquantifying particles 4 specifically binding on the surface 7 of the IC12. An assay may be any procedure used to detect the presence of atarget analyte or to quantify the concentration or amount of the targetanalyte in the aqueous sample 5. Target analytes may be enzymes,proteins, small molecules, nucleic acids, and other biological,chemical, and inorganic entities, or combinations thereof. The aqueoussample 5 may be whole blood, plasma, serum, diluted blood derivatives,spinal fluid, sputum, pulmonary lavage, fecal samples, oral samples,nasal samples, lachrymal fluid, other bodily fluids, laboratory samples,environmental samples, any other fluids potentially containing one ormore target analytes, or combinations thereof.

Further, FIG. 1 shows a filter 6 that can be placed at the top of theSPDM 8. The filter 6 may be any type of filter (e.g., membrane filter,microfilter, syringe filter) capable of blocking or trapping particulatematter (e.g., red blood cells, white blood cells, other cells and micronto millimeter size particulates) and thus removing the particulatematter from the aqueous sample 5. The filter 6 may also be adapted toremove certain biological or chemical molecules from the aqueous sample5 (e,g., a chemical coating on the filter 6 may remove molecules thatcompete with the target analyte or interfere, in any way, with theassay). Further, the filter 6 may include chemicals, molecules, andother dissolvable matter than may aid the assay protocol. For example,the filter 6 may contain dry anticoagulation factors that prevent bloodsamples from coagulating or dry assay additives to mitigate the effectsof interferers in the sample. Further still, the filter 6 may be coatedwith hydrophilic material to aid in aqueous sample 5 absorption. Thefilter can be attached onto the top surface of the SPDM using doublesided adhesive tape, transfer adhesive, hot melt adhesive, an epoxy sealalong the edge, or by heat sealing or a similar bonding process. Tominimize dead volume under the filter, the height of the double sidedtape, transfer adhesive or epoxy seal can be less than 1 um, or lessthan 5 μm, or less than 10 μm, or less than 20 μm, or less than 50 μm orless than 100 μm, or less than 250 um.

Further, FIG. 1 shows a surface capillary 15, a delivery capillary 14and a sedimentation capillary 13. The delivery capillary 14 canfluidically connect the membrane filter 6 to a surface capillary 15allowing the aqueous sample 5 to flow from the filter to the surface 7of the IC 12. The surface capillary 15 can fluidically connect thedelivery capillary 14 to the sedimentation capillary 13 thus allowingthe aqueous sample 5 to flow from the delivery capillary 14 into thesedimentation capillary 13 and up sedimentation capillary 13 to drysphere 3. In one variation of the assay system 10, the filter 6 may beplaced inside the delivery capillary 14 or surface capillary 15. Thesedimentation capillary 13 may be placed vertically over the IC 12 andin contact with reagents containing particles 4. The reagents may beconfigured in a sphere (i.e., a reagent sphere 3) or any other shape.The reagent sphere 3 or other shape may rest on top of the sedimentationcapillary 13 and may preferably be dry or lyophilized. The IC 12 may bemounted by any known method (e.g., wire-bonding, flip-chip assembly,conductive epoxy, and combination thereof) to a PCB 9. The assay system10 can be encapsulated by a casing 11 with an opening for a digitaldisplay 1 and an opening for the filter 6. The display 1 may be drivenby circuitry integrated on IC 12.

The SPDM 8 can be configured to accept an aqueous sample 5 from a samplesource (e.g., a finger stick, a pipette, a syringe, a capillary tube, orcombinations thereof), filter the aqueous sample 5 using the filter 6,deliver the filtered aqueous sample 5 first to the surface 7 of the IC12 and subsequently to the reagent sphere 3, re-hydrate dried particles4 within the SPDM 8, mix and incubate the particles 4 with the aqueoussample 5 and introduce the particles 4 onto the surface 7 of the IC. Thesystems and methods of use described herein can be applied to knownSPDMs such as those described in PCT Application No. WO 2011/059512,filed 16 Nov. 2010 (titled: FILTRATION DEVICE FOR ASSAYS) and in PCTApplication No. WO/2012/048288—MAGNETIC PARTICLE BASED BIOSENSOR, whichare incorporated by reference herein in their entirety. Othervariations, components, and functions of the SPDM 8 are furtherdescribed below.

FIG. 2 shows the aqueous sample 5 being wicked into the filter 6 whereparticulate matter such as whole blood cells can be blocked ordiscriminated by size. The aqueous sample 5 can then be wicked from theoutlet side of the filter 6 into the delivery capillary 14 and deliveredinto the surface capillary 15 and onto the surface 7 of the integratedcircuit 12, as shown by an arrow. The flow of the aqueous sample 5 cancontinue from the surface 7 of the integrated circuit 12 up thesedimentation capillary 13 to the dry sphere 3. The flow in the deliverycapillary 14, surface capillary 15 and the sedimentation capillary 13can be maintained by capillary action. Once the capillaries are filledand the dry sphere 3 fully dissolved, the flow can cease. The amount ofaqueous sample 5 in the SPDM can be precisely controlled by the innervolume of the capillaries to less than 0.5% variability, or to less than1% variability or to less than 2% variability or to less than 5%variability. The inner volume of the capillaries can be used toprecisely meter the amount of aqueous sample assayed. In cases where theassay system 10 is placed vertically as shown in FIG. 2 and the deliverycapillary 14 and surface capillary 15 are below the filter 6, gravitycan also assist the flow of the aqueous sample 5. Pressure from vacuumor pumping can also be used to facilitate the flow of the aqueous sample5 through the delivery capillary 14 and surface capillary 15. Asdiscussed above, the filter 6 may be a membrane filter and may have asurface area between 0.1 mm2 and 100 cm2 and a thickness between 1 μmand 10 mm. The membrane filter can be composed ofpolyvinylpyrrolidone/polyethersulfone (PVP/PES). The membrane filter canhave a porosity gradient to effectively trap cells in whole blood whileallowing blood plasma and the analytes therein to pass through themembrane. A preferable filter is a 0.26 mm thick PVP/PES filter with a35 μm pore size on the top and a 2.5 μm pore size on the bottom. Themembrane filter can be oriented in a horizontal plane. The membranefilter can be oriented in a plane parallel to the surface 7 of the IC12. The delivery capillary 14 can be between 0.1 mm and 10 cm in lengthand between 10 μm and 5 mm wide. A preferable delivery capillary 14 is 2mm long and 0.25 mm wide. The surface capillary 15 can be between 0.1 mmand 10 cm in length and 10 μm and 5 mm wide. A preferable surfacecapillary 15 is 5 mm long and 0.5 mm wide. The magnetic particles may bedried on the bottom surface of the filter or inside the filter.

FIG. 3 shows the aqueous sample 5 in the process of wicking upwardsinside the sedimentation capillary 13 due to capillary forces. Gravitycan also assist the flow of the aqueous sample 5 up the sedimentationcapillary 13 provided the sedimentation capillary 13 is placed below thebottom plane of the filter 6. Pressure from vacuum or pumping can alsobe used to facilitate the flow. Once the aqueous sample 5 reaches thetop of the sedimentation capillary 13, the aqueous sample 5 can dissolvethe dry reagent sphere 3 placed at the top of the sedimentationcapillary 13. The particles 4 can be released and sediment through theaqueous sample 5 to the surface 7 of the integrated circuit 12, as shownby arrows. As the particles 4 sediment, the particles 4 can react withthe target analytes in the aqueous sample 5 and bind specifically to thesurface 7 of the IC 12. The sedimentation capillary 13 can be between0.1 mm and 10 cm in length and 1 μm and 5 mm wide. A preferablesedimentation capillary 13 is 3 mm long and 1 mm diameter. The dryreagent sphere 3 can be manufactured by lyophilization and placed on thetop of the sedimentation capillary 13 using an automated pick and placetool. Alternatively, the magnetic particles can be placed in a cuvette30 by air flowing down the sedimentation capillary.

The surface 7 of the IC 12 can be illuminated by a light source 2. Thelight source 2 can generate and/or direct light to illuminate thesurface 7 of the IC 12. The light source 2 may be or include aluminescent light source such as a light emitting diode (LED), laseremitting diode, incandescent light source such as a light bulb, anyother source of light internal or external to the assay system 10, orcombinations thereof. The light source 2 may be any external lightsource (e.g., the sun, an external lamp, ambient light in a room, andany other external light source that may be used instead of or incombination with an internal light source to illuminate the surface 7 ofthe IC). The light source 2 may be positioned anywhere in the assaysystem 10 or external light may be inputted anywhere into the assaysystem 10 and an optical module may direct the light onto the surface 7of the IC 12. The light source 2 may be integrated on the IC 12 itself.For example, a direct semiconductor may be used to fabricate light 2 inthe IC 12 or a portion of a direct semiconductor may be added to the IC12 (e.g., via wafer bonding, molecular beam epitaxy, and other suitablefabrication processes). The light source 2 may be configured to producea light intensity anywhere from 1 mW/m2 to 10 kW/m2. The light sourcecan be powered by a battery to eliminate the AC tones prevalent withdistributed power sources. The light source can illuminate more than onesensing areas on one IC or more than one sensing area on more than oneICs. The activation of the light source and control of its intensity canbe done by circuitry embedded in the IC 12.

A shadow may refer to any type of light modulation caused by a particle4 in the direction of propagation of light that increases or decreasesintensity, changes the spectral composition, blocks, changes thepolarization, or otherwise modifies the properties of said light. One ormore light sources can be situated or positioned directly above theintegrated circuit 12 such that particles 4 situated above the surface 7of the IC 12 cast a shadow that is projected downward onto the surface 7of the IC. The shadow then may be detected by one or more opticalsensors 40 situated below the surface 7 of the IC 12. However, the lightsource(s) may be positioned and directed at any angle relative to thesurface 7 of the integrated circuit 12 such that the light shines onleast a portion of IC 12 surface 7. Light at or near the red spectrum(550-750 nm) may offer superior SNR since human whole blood and plasmasamples have an absorption minimum at that frequency.

In a variation of the assay system 10, multiple sources of light mayilluminate the surface 7 of the IC 12 indirectly and/or at obliqueangles. Multiple ICs can be illuminated by one source of light ormultiple sensing areas on the same IC can be illuminated by one lightsource. Alternatively, one or more sensor regions on one or more ICs canbe illuminated by more than one light source. The shadows or otherwisethe modulated light due to the particles 4 can be projected at obliqueangles (i.e., not straight downward).

One or more reflectors, one or more lenses, one or more optical fibers,one or more light pipes, and any other component or combination ofcomponents may be used to direct light onto the surface 7 of the IC 12.The light source 2 may be positioned on or integrated into the PCB 9 anda reflector placed on the ceiling of the casing 11 above the IC 12, oran optical fiber or light pipe may direct the light originating from thelight source 2 onto the surface 7 of the IC 12. The light source 2 maybe modulated (e.g. turned on and turned off repeatedly) at a certainfrequency, at multiple frequencies, following a certain predetermined orrandom sequence in time, or combinations thereof. For example, the lightsource 2 may be turned on for a predetermined amount of time prior tointroducing the particles 4 in order to calibrate the optical sensors 20on the IC 12 (e.g., by measuring the sensitivity, sensitivitydistribution, saturation level, and other relevant parameters of theoptical sensors 20 and underlying electronic circuits) and to calibratethe light source 2 (e.g., measure and adjust the light intensity, lightuniformity, and other relevant parameters of the light source 2).Subsequently, the light source 2 may be turned on for a predeterminedamount of time to allow for a shadow or any other form of lightmodulation to be created by the particles 4 and detected by the opticalsensors 20.

The SPDM 8 can be opaque such that light from the light source 2 canonly be transmitted through the sedimentation capillary 13. Multiplesedimentation capillaries above one or more ICs can allow thepropagation of light from one or more light sources to one or moresensor regions. The SPDM can be partially opaque or portions of the SPDMcan be opaque to optimize the quality of the light transmitted onto thesurface of the chip. The SPDM can be composed of two discrete portions,one opaque and one translucent or transparent. The transparent region ofthe SPDM 8 useful when there is opaque material in the sedimentationcapillary 13, like the dry sphere or lysed aqueous sample, that need tobe circumvented by the light in order to illuminate the particles 4 onthe surface 7 of the IC 12. For example, in the SPDM a thickness alongall or part of the length of the sedimentation capillary 13 can betransparent to allow the light to reach the surface 7 of the IC 12,while the rest of the SPDM 8 can be opaque. For example, the top portionof the SPDM 8 containing the cuvette 30 and to top of the sedimentationcapillary 13 can be transparent, while the bottom portion of the SPDM 8containing the rest of the sedimentation capillary can be opaque. TheSPDM can be created by laminating, gluing, or otherwise binding twolayers of material, one opaque and one transparent or translucent. Thetransmission of the light onto the surface of the chip can also be usedto determine if aqueous sample 5 has reached the top of thesedimentation capillary in the SPDM and whether the dry sphere 3 hasdissolved. Light pipes or optical fibers and capillaries 13, 14 and 15can be combined in a single unit made of plastic (PMMA, PDMS or othersilicon derivatives, polycarbonate, polyacetate, polyurethanes,polyvinylchloride, or other synthetic polymers).

Image processing filters can be used to eliminate illumination artefactsfor superior particle detection signal to noise ratio. The imageprocessing filter algorithm can be hardcoded onto the IC 12, embedded inthe memory on the IC 12 or described in software stored on the IC 12 oron an external IC. Examples of the image processing filters includespatial low pass filters, un-sharp masks, convolution matrices and otheralgorithms that combine the raw optical signals from multiple sensors ina logical algorithm to reduce or eliminate the components of the rawoptical signals that are detrimental to particle shadow detection signalto noise ratio. In this way, the image processing filter can be used forexample to estimate the background illumination, cross-talk betweenadjacent or nearby optical sensors, global shadows, bead aggregates andreflections on the surface 7 of the IC 12 due to constructive anddestructive optical interferences. The image processing filter caneliminate or reduce the shadows resulting from debris or other blemisheson the surface 7 of the IC 12 that does not correspond to a magneticparticle.

To minimize stray light from the environment or external light sources,the sample port where the sample is applied on the device, for examplethe filter opening, can have an opaque lid that closes after applicationof the sample. The opaque lid can be limited to covering only the sampleport or can large enough to cover the entire device. The opaque lid canbe hinged, screwed, clipped or fastened on.

Illumination information from the optical sensors can be interpreted bythe IC 12, which can generate the commands to direct the one or morelight sources to alter the illumination characteristics. The intensity,the color, the incident angle, the position, the coherence and thenumber of light sources and their constellation can all be directedaccording to the illumination information from the optical sensors inorder to improve detection signal to noise ratio.

Multiple light sources producing illuminations of different color can beused to identify magnetic particles of different color. A first lightsource 200 can produce an illumination of a first color 201 and a secondlight source 210 can produce an illumination of a second color 211 ontothe surface 7 of the IC 12. A first particle 202 can be dyed or coloredwith color 201 and a second particle 212 can be dyed or colored withcolor 211. Particles 202 and 212 can bind specifically atop opticalsensors embedded in the IC 12. For equivalent illumination intensitiesfrom light source 200 and light source 210, the intensity of the shadowcast by particle 202 on the optical sensor resulting from theillumination of light source 200 will be different from the intensity ofthe shadow cast by particle 202 on the optical sensor resulting from theillumination of light source 210. Similarly, for equivalent illuminationintensities from light source 200 and light source 210, the intensity ofthe shadow cast by particle 212 on the optical sensor resulting from theillumination of light source 200 will be different from the intensity ofthe shadow cast by particle 212 on the optical sensor resulting from theillumination of light source 210. The color of a particle can bedetermined by measuring the relative intensities of the shadowsresulting from light sources of different color. The lights of differentcolor can be turned on sequentially or at the same time. The opticalsensors can identify the color of a colored particle by measuring one ormore frequencies of the absorbance, reflectance, transmittancephosphorescence, or fluorescence spectrum of the shadow cast by acolored particle. The color of the shadow is the complementary of theparticle. More than one light source of more than one color can be usedto illuminate the colored particle with more than one wavelength oflight, thereby providing a spectral signature of the colored particle. Abroad spectrum light can be used for calibration. Various intensitiescan be used for various illumination colors and the relative intensitiesof the shadow, or absorbance, reflectance, luminescence, fluorescence,phosphorescence or transmittance of the colored beads can be used toidentify the color of the bead. Mono-chromatic, or multi-chromaticlights can be used. Coherent, collimated or diffuse lights can be used.Optical sensors sensitive to different detection spectrums can detectthe shadows from colored particles and thereby can identify the color ofthe particle. A single optical sensor that can measure illuminationintensities at different optical frequencies can be used to determinethe color of a particle casting a shadow on it.

Multiple optical sensors sensitive to different optical spectra can beused to determine the color of a particle. The cross sectional area ofthe optical sensors can be smaller than the cross sectional area of theshadow of the colored particle so that they can be laid out to measurethe intensity of the shadow from the same particle.

Optical sensors that are sensitive to different optical spectra can beactivated to detect the same shadow at the same time, or they can beactivated to detect the same shadow in an alternating sequence.

Particles of the same color can be coated with one or more reagents thatreact specifically to one or more targets such as epitopes or one ormore chemical groups or moieties on the same target. Particles ofdifferent color can be coated with different reagents that reactspecifically to different targets. Particles 202 can be coated with afirst antibody 222 and particles 212 can be coated with a secondantibody 232. Particles 202 and 212 can be dried in the same dry sphere3 or can be dried in separate dried spheres. Particle 202 and 212 cansediment in the same sedimentation capillary 13 or sediment in separatesedimentation capillaries. The surface of the chip can be coated withchemical reagents that bind specifically in a capture format to particle202 in the presence of a first specific target 242. The surface of thechip can be coated with chemical reagents that bind specifically in acapture format to particle 212 in the presence of a second specifictarget 243. Particles of different colors can be selectively identifiedand the concentration of their targets measured at the same time or insequence. Multiplexed assays can be performed simultaneously on the samechip. The number of particles of the same color can range from 1 to100,000 to 1 trillion. The number of different colors can range from 1to 1000. Each target can have a unique color, or multiple targets canshare one color or one color can identify multiple targets.

Examples of Multiplexed Embodiments

1—entire chip is coated with a mixture of antibodies and all particlesof the same color are derivatized with a specific antibody;2—specific sites of the chip are derivatized with 1 specific antibody.Using specific colored particles (such as beads) per assay allowsdetermination of cross-reactive binding when wrong color beads is at thewrong location;3—when a certain bead is derivatized with multiple antibodies,multiplexing is preferably achieved by derivatizing specific locationsof the chip with specific antibodies.

The IC 12 can be a substrate that can incorporate one or more opticalsensors 20 and associated electronic circuits. At least a portion of thesurface 7 of the IC 12 is coated with reactive molecules and the IC 12is configured to accept particles 4 that may bind specifically (i.e.,via the reactive molecules) or non-specifically to the surface 7 of theIC 12, depending on the concentration of the target analyte. The IC 12may be used to remove from atop the sensors any non-specifically boundparticles and quantify the number or concentration of remainingspecifically bound particles. The number of specifically bound particlesmay be proportional to the concentration of the target analyte in thesample. Generally speaking, specifically bound particles are particlesthat are bound to a surface 7 via at least one specific bindinginteraction (i.e., antibody-antigen binding). Generally speaking,non-specifically bound particles are particles that are bound to thesurface 7 with weaker binding forces (e.g., van der Waals forces).Specifically bound particles refer to particles that are bound with oneor more specific biochemical interactions such as one or moreantigen-antibody binding interactions and other interactions discussedabove and are not removed from the surface 7 by on-chip generatedmagnetic separation forces. Non-specifically bound particles may beparticles that are removed from the sensing area 21 by on-chip generatedmagnetic separation forces. Non-specifically bound particles may stillcontain one or more specific binding interactions but generally containfewer specific binding interactions than specifically bound magneticparticles. For example, for large particles (e.g., those greater than100 nanometers in diameter), multiple specific binding interactions maybe required for the particles to remain stationary in the presence ofseparation forces (i.e., to be considered specifically-bound). Forexample, particles with 2 or more antigen-antibody binding interactionsmay be never removed with separation forces and thus are alwaysconsidered specifically bound, particles with fewer than oneantigen-antibody binding interactions may be always removed withseparation forces and thus are considered non-specifically bound,whereas particles in between may be either specifically-bound ornon-specifically bound. The magnetic separation forces can be tailoredto select the desired number of antigen-antibody interactions necessaryto keep a magnetic particle specifically bound to the surface. In sodoing, the number of magnetic particles remaining specifically bound tothe surface can also give an indication of the total number ofantigen-antibody interactions attaching the particles to the surface 7of the IC 9.

The bio-chemical functionalization and the magnetic forces can betailored to ensure that only 1 specific molecular interaction (such asone antigen-antibody interaction, one strand of DNA, a complementarystrand of DNA, a covalent bond, a hydrogen bond, is sufficient tospecifically bind a magnetic particle to the surface 7 of the IC 12.Magnetic particles larger than 100 nm, such as between 100 nm and 1 um,or between 1 um and 10 um, can also be configured in the system to bindspecifically to the surface 7 of the IC 12 through one single specificmolecular interaction. The on-chip generated magnetic separation forcescan be tailored to pull away from the sensors the magnetic particlesthat have no specific molecular interactions to the surface. The on-chipgenerated magnetic separation forces can be tailored to leaveimmobilized the magnetic particles that have exactly one specificmolecular interaction to the surface. A magnetic particle sensor candetect a single magnetic particle and by extension, a magnetic particlesensor can be used to detect a single specific molecular interactionbetween the surface 7 of the IC 12 and a magnetic particle. An array ofindividually addressable magnetic particle sensors can be used to detectmultiple magnetic particles specifically bound to the surface 7 of theIC 12 through single specific molecular interaction. The array ofmagnetic particle sensors can be used to count the number of specificmolecular interactions in the sensing area on the surface 7 of the IC12.

The assay system 10 can be handheld and portable. It can be less than 1L, 0.1 L, 0.01 L, or 1 mL in volume and weigh less than 1 kg, 100 g, 10g or 1 g.

Particles may serve as light concentrators through internal or externalreflections. For example, the amount of light incident on opticalsensors 20 may be increased by over 1% and optical sensors on the IC canbe configured to detect this light intensity increase. The particles maymodulate the light (e.g., filter the frequency spectrum of the light,luminesce with another frequency of light, change the color orpolarization of the light, fluoresce, or phosphoresce). Likewise, theoptical sensors 20 may be configured to detect any of these color orpolarization changes, for example by using color or polarization filterarrays placed over the optical sensors 20 or by using different opticalsensor 20 types such as N-well diodes, N+ diodes, poly gate diodes, andP+ diodes, which are sensitive to different optical spectra orfrequencies. The electronic circuits may be any combination of metal orsemiconductor connections, resistors, capacitors, inductors,transistors, diodes, amplifiers, digitizers, digital logic, and otherintegrated electronic circuits used to obtain, forward, process, andoutput a signal from the optical sensors 20. The circuitry may be usedto individually address any of the optical sensors 20 in an array,either sequentially or in parallel. The IC may be fabricated in anycommercial integrated circuit process (e.g., CMOS, CCD, BJT) or may bemade in a custom fabrication process. Other variations, components, andfunctions of the IC 12 are further described below. Optical sensors 20can distinguish between different color beads by the relative amount oflight they transmit from the different color light sources. Opticalsensors 20 can distinguish different wavelengths of light that areemitted by different particles such as beads.

The PCB 9 can be any rigid or flexible substrate that stores the IC 12and electrically and/or mechanically connects the IC 12 to any othercomponents. The PCB 9 can contain one or more batteries, one or morecontrol modules, one or more voltage regulators, one or more sensors,one or more actuators, one or more displays, and combinations thereof.As discussed above, the PCB 9 may also include the light source 2 thatcan provide light into the IC 12 via an optical module. The PCB 9 may beplaced on the bottom of the housing or in any other position in thehousing and may contain connectors and daughter-boards or any otherextensions that may contain any of the components described above ordescribed below in any position and orientation inside or outside thehousing containing the SPDM 8. The PCB 9 components internal to theassay system 10 and the circuitry and sensors of the IC 12 may becontrolled by a control module integrated on the IC 12 (e.g., a controlmodule core, a discrete control module mounted on the PCB 9, a centralprocessing unit (CPU), a digital signal processing (DSP) unit, afield-programmable gate array (FPGA), or any other control module orcombination of control modules. The terms control module core andcontrol module may be used interchangeably in this specification and maybe located on the PCB 9, in the IC, or in any other part of the assaysystem 10. The control module may store assay calibration parameters andassay protocol algorithms. Assay calibration parameters may include astandard curve that relates the number or concentration of particles 4detected to the concentration and/or amount of the target analyte in theaqueous sample 5. Assay calibration parameters may also include an assaytime which may include any time intervals between different steps in anassay (e.g., time from aqueous sample 5 detection to optical sensorarray readout, readout duration, magnetic separation force duration,magnetic separation intervals and any other time interval). Assaycalibration parameters may also include magnetic separation force andmagnetic concentration force strength, duration, frequency, pattern.Assay calibration parameters may include any other parameters that mayaffect assay results. The assay calibration parameters are adjusted inresponse to measurements made by any sensors and components of the assaysystem 10. The battery or the battery unit can be removed in an easypop-out system or otherwise separated prior to discarding the system.Portions of the circuitry or the entire electronic module includingdisplay can be popped out or separated from the rest of the device priorto discarding the system.

The assay system 10 can contain one or more inertial sensors. Theinertial sensors may include accelerometers, gyroscopes, tilt sensors,and any other sensors capable of detecting and quantifying position,velocity, acceleration, orientation, and combinations thereof. Theinertial sensors are configured to sense the physical parametersdiscussed above and output them to the control module. The controlmodule may be configured to read the output from the inertial sensorsand determine if any of the physical parameters are unusual and/or outof the acceptable range. For example, the inertial sensors may send anoutput to the control module indicating that the orientation of theassay system 10 is incorrect (e.g., the IC 12 is at on a tilt for aprolonged period of time) or the acceleration of the assay system 10 istoo high (e.g., a user is moving the assay system 10 beyond therecommended limits while the magnetic separation is being performed). Asa result, the control module may send a signal to the user via thedisplay 1 that an incorrect action took place and that the results ofthe assay are invalid. The control module may send a signal to the uservia the display 1 that an incorrect action took place and that theposition of the device must be adjusted in order for the assay toproceed normally. Alternatively, the control module may attempt tocompensate for any effects resulting from incorrect orientation and/orapplied acceleration. The control module can modify and/or selects theassay calibration parameters based on the measured values of relevantphysical parameters. The control module can perform more detailedcompensation on the sensor level, for example, by applying differentweights to signals from different optical sensors 20 positioned indifferent locations on the IC, or completely ignoring the reading fromcertain optical sensors 20 altogether. The control module may alsomodify the assay time based on the reading obtained from the inertialsensors (e.g., the optical detection may be turned on sooner/later,allowing particles 4 less/more time to incubate with the target analyte,respectively). The inertial sensors may be mounted in any component ofthe assay system 10 (e.g., mounted as a chip on the PCB 9, integratedinto the IC, mounted on any wall of the casing 11, or combinationsthereof).

The optical sensors and other sensors can be used to validate themanufacturing of the assay system 10. The assay can be invalidated iftoo many or too few magnetic particles are detected on the surface 7 ofthe IC 12. Too few magnetic particles can be an indication of the assaysystem 10 being tilted during use, while too many particles may be anindication of a manufacturing process problem. The assay can also beinvalidate the assay if the surface density of the magnetic particlesdetected is not approximately uniform. This can also be an indicationthat the assay system 10 was tilted during use. The assay system 10 canalso detect aqueous leaks in the double-sided tape by monitoring whetherthe magnetic particles move across the surface 7 of the IC 12 when nostrong magnetic forces are applied.

The PCB 9 and/or the IC 12 may contain a read-only memory module (ROM),a random access memory module (e.g., SRAM, DRAM), or other modulecapable of storing data (PROM, EPROM, EEPROM, Flash, and any otherstorage medium). The data module may be part of the control module andmay be used to store calibration data from the various sensors,actuators, and modules in the assay system 10 that is derived justprior, during, or after performing an assay. The data module may storecalibration data generated during the design process or after the IC 12is manufactured and/or the assay system 10 is assembled. For example,the calibration data may compensate for variations in manufacturing(e.g., ILD thickness, optical sensor 40 sensitivity, and otherparameters that may vary during manufacturing). In another example, thecalibration data may compensate for variations in surface coating (e.g.,surface chemistry, reactive molecule density, reactive molecule type,and other parameters that can vary during surface 7 coating). Thecalibration data can include assay calibration parameters that arederived from one or more chips in a particular batch (e.g., from thesame wafer, same surface coating batch, same assembly batch).

The assay system 10 can include one or more temperature sensors. Thetemperature sensors may include a thermistor, a semiconductor sensor, athermocouple, a temperature-dependent resistor, or combinations thereof,and may be configured to measure the temperature of the surroundings(e.g., the air temperature outside the assay system 10, the temperatureof the SPDM 8, and/or the temperature in the vicinity of the IC 12) orthe temperature of the aqueous sample 5 directly (e.g., the SPDM 8 maybe configured to place the temperature sensor in contact with theaqueous sample 5, or the sensor may be located at or near the surface 7of the IC 12). An assay may have distinct assay calibration parameters(e.g., standard curve, assay time) at each temperature level and as theassay kinetics may be sped up or slowed down depending on thetemperature level. Accordingly, the temperature reading may be sent tothe control module and may be used to adjust the assay calibrationparameters to compensate for the changes in temperature. Aside frombeing integrated or attached to the PCB 9, the temperature sensor may bemounted in any other component of the assay system 10 (e.g., integratedinto the IC 12, mounted on any wall of the casing 11, or combinationsthereof). The IC 12 or SPDM 8 may contain one or more heating elements(e.g., resistors, coils, wires) that can be used to keep the temperatureof the surface 7 of the IC 12, the aqueous sample 5, and/or the entireassay system 10 at a nearly constant, predetermined value. Theinformation from the temperature sensors can be read and the controlmodule can control the heating elements in order to keep the temperatureconstant in the range of 20° C. to 40° C.

The assay system 10 can include one or more moisture sensors. Themoisture sensor(s) may be placed in contact with the aqueous sample 5and may be used to detect the presence of the aqueous sample 5 (e.g.,using electrodes to detect a change in resistance or a change incapacitance between the electrodes as a result of the presence of theaqueous sample 5). The moisture sensor(s) may send a signal to thecontrol module, either continuously or upon detection of the aqueoussample 5, indicating the moisture level reading, and the control modulemay enable other components of the assay system 10 upon receiving asignal indicating the presence of the aqueous sample 5. Aside from beingintegrated or attached to the PCB 9, the moisture sensor may be mountedin any other component of the assay system 10 (e.g., integrated into theIC 12, mounted on any wall of the casing 11, or combinations thereof).

The PCB 9 can include one or more viscosity sensors. A viscosity sensorcan be placed in contact with the aqueous sample 5. The viscosity ofblood plasma can vary. Higher fluid viscosities may lead to longer assaykinetics and longer particle sedimentation times. Accordingly, theviscosity sensor(s) may send a measurement of the viscosity to thecontrol module which in turn may modify the assay time and other assaycalibration parameters. Aside from being integrated or attached to thePCB 9, the viscosity sensor(s) may be mounted in any other component ofthe assay system 10 (e.g., integrated into the IC 12, mounted on anywall of the casing 11, or combinations thereof). By includingtemperature, viscosity, orientation, acceleration, and any otherenvironmental factors into account when performing an assay, the resultsof the assay may be adjusted appropriately, via the assay calibrationparameters, to effectively cancel out these environmental effects,leading to increased robustness, accuracy, and consistency of results indiverse environments and settings. The moisture sensors placed atdifferent points along the path of the aqueous sample 5 can be used tomeasure the viscosity of the fluid. Alternatively or in combination, theoptical sensors 20 can be used to measure the time from the reagentsphere 3 dissolution to the time the particles 4 sediment onto thesurface 7 of the IC 12. This time can also be used to determine theviscosity and incubation time information.

The assay system 10 can include a vibrator module. The vibrator modulemay include an electric or piezoelectric motor with an unbalanced mass,a piezoelectric or electromagnetic acoustic or ultrasonic transducer, orany other module and method for generating vibrations. The vibratormodule may be turned on during the sample delivery steps (i.e., betweenthe time when the aqueous sample 5 is introduced and the time theparticles 4 finish sedimenting on the surface 7 of the IC 12) in orderto agitate the aqueous sample 5 and/or the particles 4 and allow theparticles 4 to more quickly disperse in the aqueous sample 5 and speedup assay kinetics. The vibrator module may be enabled upon detection ofthe aqueous sample 5 when the aqueous sample 5 comes in contact with theSPDM 8 and/or the IC. The amplitude, frequency, and/or pattern of thevibrations can be controlled by the control module and adjusted based onvarious parameters obtained from the environmental sensors discussedabove and based on any assay calibration parameters. For example,vibration amplitude may be increased if the temperature is low and/orthe viscosity of the aqueous sample 5 is high in order to speed up assaykinetics.

A capacitive, inductive or resistive humidity sensor can be used todetect the presence of the aqueous sample 5 on the surface of the IC 12.The humidity sensor can be embedded in the IC 12 under the sedimentationcapillary 13 or under the surface capillary, or under the deliverycapillary.

The PCB 9 can contain one or more external electromagnets or permanentmagnets generating fields from 0.1 μT to 1 T at excitation frequenciesfrom DC to 100 MHz. Magnets can have an appreciable effect on theparticles 4 if the particles 4 are magnetic particles. A permanentmagnet may be placed below the IC 12 or in close proximity to the IC 12in order to pull magnetic particles more quickly towards the surface 7of the IC 12 (i.e., increase the sedimentation velocity of the magneticparticles to as high as 10 mm per second). The permanent magnet may bereplaced with an electromagnet (e.g., Helmholtz coil, current line, orcombinations thereof) mounted onto the PCB 9 and below the IC 12 toselectively generate magnetic fields and magnetic forces. A secondelectromagnet may be placed above the IC 12, near the ceiling of thecasing 11, in order to pull the magnetic particles up from the sensorsurface 7. This could be used to increase the incubation time to over 10minutes or to perform magnetic separation steps. One or moreelectromagnets may be placed on the sides of the PCB 9 around thesedimentation capillary or extend into the assay system 10 and aroundthe sample chamber in order to generate lateral forces on the magneticparticles. Any of the electromagnets placed above, below, or to thesides of the sample chamber may be used to agitate the magneticparticles (e.g., move them side to side, make them vibrate, make themchange orientation) in order to create convective forces in the aqueoussample 5 and/or to more quickly sediment the magnetic particles to theIC 12 surface 7. Electromagnets configured to generate lateral forcesmay be used to compensate for any tilt in the assay system 10 (e.g., ifthe assay system 10 is tilted to the left, an electromagnet on the rightside may turn on to ensure magnetic particles sediment evenly and do notaggregate on the left side of the IC). The permanent magnets orelectromagnets may be mounted in any other component of the assay system10 (e.g., integrated into the IC, mounted on any wall of the casing 11,or combinations thereof).

The assay system 10 can be run with the IC 12 at the top and with itssurface 7 facing down. A permanent or electromagnet can be placed abovethe IC 12 to pull the magnetic particles 4 upward to its surface. Inthis way, the system can run without the filter directly on whole bloodsince the red blood cells will settle downwards, away from the surfaceof the IC. Alternatively, the system can be run directly with lysedsamples. The whole blood filter can be replaced by or stacked with ahydraulically permeable solid membrane or matrix to ensure even andefficient mixing of the cellular material with a lysing agent and otherdry reagents.

The display 1 can be any display known in the prior art (e.g., LCDdisplay, LED display, OLED display and any other type of display,touch-screen) that may display the presentable assay informationgenerated or stored by the chip 12 (e.g., concentration of one or moretarget analytes, amount of one or more target analytes, coefficient ofvariance, timestamp, timing of the assay, validity of the results,patient and device identification number, temperature, humidity,internet/telephone/physical locations, help/counselling and information,angular information of the device, device ID, patient ID and any otherrelevant results). The presentable assay information may include statusindicators that can signal the device is ready, busy, testing, done, orin an error state. The presentable assay information can include errormessages that indicate the device is tilted, additional sample isneeded, the on-board controls failed to fall within expected range,temperature or humidity over/under the specified range or an expirationdate has been exceeded. The presentable assay information may includeinformation on the sample (e.g. whether it is lysed, the viscosity,turbidity, lipemia, color of sample). The presentable assay informationmay include written or visual instructions to the user on how to use theassay system 10 to perform a measurement. A speaker or earphone jack mayalso be integrated into the assay system 10 to deliver the presentableassay information in an audio format.

The presentable assay information can be displayed in an encryptedformat alone or alongside the presentable assay information in anon-encrypted format. The display 1 can also display a portion or all ofthe presentable assay information as a one dimensional bar code or 2dimensional QR code or other machine-readable format. The results canappear as an encrypted hexadecimal code or using other symbols orshapes. Users can take one or more still photographs or one or morevideos of the display 1 using a secondary mobile device to retrieve anddecrypt a portion or all of the presentable assay information. The usercan have a medical software application installed on a secondary mobiledevice that processes the photograph or video of the display to retrieveand decrypt the presentable assay information. The medical softwareapplication can prompt the secondary mobile device's user for a patientID or can retrieve directly from the secondary mobile device's logininformation. The presentable assay information retrieved by taking thephotograph or video of the display can be bound to the patient ID in asecure manner, for example in a HIPAA compliant manner. The display canbe deactivated or the presentable assay information can be removed fromthe display after a pre-set time, or once a user presses a button or thea touch-screen integrated into assay system 10 or from a prompt from themedical software application. Tele-communication by taking stillphotographs or videos of the display 1 does not require any additionalhardware either on the assay system 10 or on the secondary mobile deviceand is therefore universally interoperable with all modern consumersmart devices.

The medical software application can also store the presentable assayinformation on the secondary mobile device and can graph the presentableassay information. The medical software application can combine thepresentable assay information with historical medical information fromthe patient. The medical software application can connect the secondarymobile device wirelessly or through a wire to a third storage device forprocessing and storing the presentable assay information. The medicalsoftware application can store or transmit all or portions of thepresentable assay information to a third device.

Presentable assay information can be transmitted to and stored on thesecondary mobile device without being displayed on display 1. Themedical software application can prompt the user to get in contact witha doctor, counselor, insurance company representative, drug companyrepresentative, clinical trial representative, a reporting agency orother third party in order to gain access to the presentable assayinformation. The medical software application can automatically contacta third party and direct transmission of all or part of the presentableassay information to that third party. Example includes the CDC or otherhealthcare professionals in the cases where public safety is at risk.The medical software may omit the patient ID when sending informationthird parties, but can include information like the time and location ofsecondary wireless device . The medical software application can combinethe presentable assay information with other information found on thesecondary wireless device, such as time of day, location, logininformation, contact to healthcare professionals, emergency contacts,age and sex of patient or other patient information stored on thesecondary mobile device

The medical software application can be stored on the chip 12 or inother storage devices integrated in assay system 10 and transmitted tothe secondary mobile device prior to performing the assay, after runningthe assay or during the assay. The web location and/or routinginformation of the medical software application can be stored on thechip 12 or in other storage devices integrated in assay system 10 andcan be included in the presentable assay information. The assay system10 can prompt the secondary mobile device to download the medicalsoftware application by transmitting the web location or routinginformation.

The device can also provide multiple different sets of results. A firstset of displayed results can be displayed and provided to the user and asecond for example more detailed set of comprehensive results can besent to a third party.

A patient or user untrained as a caregiver, such as a family member orhome health aide, can perform the assay without help from trainedhealthcare professionals. For special applications like drug monitoringor emotionally difficult applications like HIV testing, it may beundesirable for the patient to examine all or part of the presentableassay information prior to their examination by a third party. Thedevice can encrypt and transmit some or all the presentable assayinformation to a third party for review without displaying them orgranting access to them to the patient. The third party can review thepresentable assay information and re-transmit reviewed assay informationback to the patient, or re-transmit access to the presentable assayinformation, or re-transmit a different set of information or additionalinformation. The patient or user may be required by the device to sendthe presentable assay information the secondary mobile device to a thirdparty in order to receive the reviewed assay information or access tothe latter. The presentable assay information can be encrypted in a waythat can only be decrypted by the third party. The patient may or maynot be the user of the secondary mobile device or the assay system 10. Ahealthcare professional, a family member or an untrained home healthaide may or may not be the user of the secondary mobile device or theassay system 10. The secondary mobile device can be a tablet, a phone orany wireless telecommunication device.

Presentable assay information and the medical software application canbe relayed to the secondary mobile device wirelessly by assay system 10(for example using Bluetooth, Zigbee or Wifi protocols), visually on thescreen, capacitively using parallel plate, inductively or via opticallinks such as IR communication or taking still photographs of thedisplay 1. The assay system 10 can contain full duplex communicationwith a transceiver device. The assay system 10 can have an optical linkor a bar code reader integrated into it. The transceiver device can sendto the assay system 10 information regarding which assays were ordered,and additional patient information like sex or age of patient or otherpertinent information to the assay. The assay system 10 can modify theassay according to the received information. In a multiplexed format,some assay may not be run, or may be run but not reported if theyweren't ordered.

The casing 11 can be an external shell that houses all the othercomponents of the assay system 10. The casing 11 may be made in anystandard or custom manufacturing process (e.g., injection molding) andmay be made from any standard material (e.g., plastic). The casing 11may also include an outer flap over the sample inlet or over the entiredevice to reduce the amount of light that can shine through the seams ofthe casing 11.

The IC 12 can include one or more optical sensors 20 configured in anarray. Each optical sensor 20 may be integrated into the IC 12 andimplemented in any technology (e.g., junction photodiodes, avalanchephotodiodes, PIN photodiodes, active pixel sensors, charge-coupleddevices, light-sensitive resistors, or other solid-state optical sensors40). Each optical sensor 20 may be individually addressable and mayoutput electrical signals that may be amplified, digitized, stored andprocessed by circuitry on the IC 12 and/or the PCB 9. Each opticalsensor may be configured to detect a shadow cast by a particle as aresult of the particle blocking the light rays from the light source.For example, an optical sensor can detect a particle because theparticle casts a shadow over the sensor, decreasing the light intensityincident on optical sensor from the light source. Consequently, as aresult of a particle blocking a portion of the light from the lightsource, optical sensor generates a signal that is different from abaseline signal without the particle, thus indicating the presence of aparticle over the sensor.

Magnetic particles in the sensing area 21 on the surface 7 of the IC 12can be detected by magnetic sensors integrated in the IC 12 as inWO/2009/091926—INTEGRATED MAGNETIC FIELD GENERATION AND DETECTIONPLATFORM, reference here in its entirety. Hall sensor, GMR sensors, AMRsensors, variable inductance current lines can all be used as magneticsensors. If magnetic sensors are employed, the light source 2 can beomitted.

FIGS. 4A, 4B, and 4C show a top and a cross sectional view,respectively, of the light source 2 and the IC 12. One or more magneticseparation field generators can be embedded in the integrated circuit 12at a lateral distance of 0.1 μm to 100 μm from the sensing area 21.

A portion of the magnetic particles 24 that sediment to the surface 7 ofthe IC 12 and may bind strongly through specific bio-chemical orinorganic interactions to the surface 7 of the IC 12. A portion of themagnetic particles 25 that sediment to the surface 7 of the IC 12 maybind weakly to the surface 7 of the IC 12 through non-specificinteractions.

The assay can be performed in various assay formats. In a capture assayformat, the presence of one or more target analytes would promotespecific binding of the particles 4 to the surface 7 of the IC 12. In acompetitive assay format, the presence of one or more target analyteswould inhibit specific binding of the particles 4 to the surface 7 ofthe IC 12. In a derivative capture format, one or more by-products ofone or more reactions with the target analyte would promote specificbinding of the particles 4 to the surface 7 of the IC 12. In aderivative competitive format, one or more byproducts of one or morereactions with the target analyte would inhibit specific binding of theparticles 4 to the surface 7 of the IC 12. Multiple assay formats can beperformed concurrently on the same chip 12, or on the same assay system10 with multiple chips. Electrodes and other bio-sensors can beintegrated on the same chip to detect ions, electrolytes and generalchemistry analytes.

The magnetic separation field generators can be used to remove thenon-specifically bound magnetic particles from the sensing areas 21 sothat the optical sensors 20 only detect specifically bound magneticparticles. The magnetic separation field generators can be implementedas electrical separation conductors 23 embedded in the integratedcircuit 12 and routed in proximity to the sensing area 21. Currentpassing through the separation conductors generates magnetic forces thatact on the magnetic particles inside the sensing area. The current canbe from 0.01 mA to 200 mA depending on the separation force desired. Avalue for the current passing though separation conductors to separate2.8 μm magnetic particles can range from 1 mA to 100 mA. The separationconductors 23 on either side of the sensing area 21 can be activated atdifferent times in order to pull the magnetic particles. The current canbe toggled between the two separation conductors at a frequency from0.001 Hz to 100 MHz. The magnetic separation forces can be strong enoughto displace non-specifically bound magnetic particles from the sensingarea towards the separation conductor, but not strong enough to displacespecifically bound magnetic particles. A sequence of magnetic separationforces is a series of magnetic forces resulting from modulating one ormore currents through one or more magnetic separation conductors. Thesequence of magnetic separation forces can be controlled by an algorithmstored on the IC 12.

Non-specific binding forces may be on the order of 0.1 pN to10 pN, whilespecific binding forces may be on the order of 20 pN to 20 nN. Forexample, magnetic particle 24 may sediment over optical sensor 26 andmay specifically bind to the surface 7 of the IC 12 over optical sensor26. Thus, magnetic particle 24 may not be removed by the separationforce generated by a separation conductor 23 placed laterally to thesensing area 21 and may be detected by optical sensor 26. On the otherhand, magnetic particle 25 may sediment over optical sensor 27 and maynot bind specifically (i.e., non-specifically bound) to the surface 7 ofthe IC 12 over optical sensor 27. Thus, magnetic particle 25 may beremoved by the separation force generated by the conductors placedlaterally to the sensing area 21 and may not be detected by opticalsensor 27. The electric currents used to generate magnetic forces may bepre-programmed onto the IC 12 during the design process or afterfabrication and may be adjusted at a later stage (e.g., before the assayor dynamically during the operation of the assay) depending on variousparameters (e.g., temperature, viscosity of the aqueous sample 5,magnetic content of the magnetic particles, size/shape of the magneticparticles, and other factors). Magnetic forces can be generatedexternally to the integrated circuit 12 using one or more permanentmagnets or external electromagnets (e.g., coils integrated onto the PCB9). In a variation of the assay system 10, magnetic separation fieldgenerators may be omitted altogether from the IC 12.

FIG. 5A is a cross sectional side view of the dry sphere 3 placed in acuvette 30 with vertical side walls 32. The cuvette can be of any shapeincluding square, rectangular, cylindrical and can be smaller, greateror equal to the volume of the dried sphere 3. The cuvette 30 can also beequal to or slightly narrower than the diameter of the dried sphere 3 inorder to hold it motionless in place. The cuvette 30 can be wider thanthe dry sphere 3.

To promote the complete dissolution of the dried sphere 3, the cuvette30 can fill completely with the aqueous sample 5 as shown in FIG. 5B.The fill stop structure 31 can be an enlarging of the cuvette, a stopgap or a stop material.

To promote complete dried sphere 3 dissolution, the diameter of thedried sphere 3 can be similar to the diameter of the sedimentationcapillary 13. For example the diameter of the dried sphere 3 can bebetween 25% and 50%, between 50% and 75%, between 75% and 850%, between85% and 100%, between 100% and 115%, between 115% and 125%, between 125%and 150% or between 150% and 200% of the diameter of the sedimentationcapillary 13.

To promote complete dry sphere 3 dissolution, the depth of the cuvettecan be similar to the diameter of the dried sphere. For example thedepth of the cuvette 30 can be between 10% and 25%, between 25% and 50%,between 50% and 75%, between 75% and 100%, between 100% and 125%,between 125% and 150% or between 150% and 200% of the diameter of thedried sphere 3. The cuvette 30 can be partially filled with the aqueoussample 5 or the cuvette can remain unfilled with the dry sphere 3dissolving fully into the sedimentation capillary 13 below without anyfluid entering the cuvette 30.

FIG. 5C shows the bottom of the cuvette acting as the fill stopstructure.

FIG. 6 is a cross sectional side view of a cuvette with tapered sidewalls 40. The tapered sidewalls can hold the dried sphere 3 in placefirmly. The tapered sidewalls 40 can be designed to wick the aqueoussolution 5 via capillary force up the entire length of the taperedsidewall 40, or up a portion of the tapered sidewall 40. The taperedsidewalls 40 can be made to prohibit the wicking of the aqueous solution5.

FIG. 7 is a cross sectional side view of a cuvette 30 with a cover 50 tohold the dried sphere 3 stationary. The cover 50 can be manufactured ofa breathable or porous material to let air pass, or can be fully orpartially hermetic to eliminate or reduce evaporation of the aqueoussample through the top of the sedimentation capillary 13. In the casethat the cover 50 is hermetic, an air opening 51 can be implemented tolet the trapped air evacuate as the aqueous solution 5 approaches. Theair opening can be designed into the SPDM 8 or into the cover 50. Thecover 50 can also be transparent or partially transparent to let lightilluminate the dry sphere 3 and down the sedimentation capillary 13after the dry sphere 3 dissolves. In this case, the optical sensorsembedded in the IC 9 can detect when the dry sphere 3 has dissolved. Thecover 50 can press on the dry sphere 3 in order to keep it motionless inthe cuvette. To eliminate adhesion of the dry sphere 3 to the cover 50,the bottom of the cover 50 inside the cuvette 30 can be made adhesionfree. The cover can be glued, taped, thermally bonded, or snap fit intolocation.

FIG. 8 is a cross sectional side view of the surface capillary 15constructed from double sided tape 60. A channel can be cut, punched ormilled into double sided tape 60 or transfer adhesive or epoxy and thatchannel can form the sidewalls of the surface capillary 15. The doublesided tape 60 can provide a hermetic seal on the surface of the chip 12.The surface 7 of the IC 12 can be smaller than the bottom surface of theSPDM in such a way that the bottom surface of the SPDM completelyoverlaps the surface 7 of IC 12. Otherwise, any undesirable gaps in thedouble sided tape 60 could result in persistent leaks that can pool onthe surface 7 of the IC 12.

The double sided tape 60 may be replaced by or used in combination withother adhesives such as silicones, acrylates, epoxies or others. Acompression seal can be used instead of or in combination withadhesives; in this case, the double sided tape 60 may be replaced by aflexible gasket, and mechanical pressure could form the seal between theIC 10 and the SPDM 8. Alternatively, the SPDM could be made out offlexible material such as rubber or silicone, and the surface capillary15 could be formed in the bottom surface of the SPDM, without any gasketor tape. The height of the double sided tape 60 or transfer adhesive canbe less than 250 μm, for example between 1 μm and 10 μm, or 10 μm and 25μm, or 25 μm and 50 μm, or 50 μm and 100 μm or 100 μm and 250 μm. Athinner adhesive reduces the void volume of the surface capillary 15 andbring the aqueous samples 5 in closer proximity to the surface 7 of theIC 12 for on-chip pre-treatment of the aqueous sample 5. A thick tapecan be used to ensure a hermetic seal despite non uniformities on thesurface 7 of the IC 12 or on the bottom interface of the SPDM 8.

FIG. 9 is a top view of the surface of the integrated circuit 12 withthe double sided tape 60 mounted on it. The sensing area 21 can besituated under the sedimentation capillary 13, while the active area 71can be situated along the length of the surface capillary 15. Under theactive area, a number of solid state devices can be integrated for thepre-treatment of the aqueous sample 5 as it flow by into thesedimentation capillary 13. One or more temperature sensors and heatingelements can be embedded under the active area 71 to heat the aqueoussample 5 as it flows by and measured the temperature of sample 5. Thetemperature of the SPDM or the temperature of the aqueous sample in theSPDM can be adjusted and kept at constant temperature for isothermalnucleic amplification of oligonucleotides, or the temperature can becycled for PCR amplification of oligonucleotides. Similarly, one or morepH sensors and hydrolysis electrodes or other pH adjusting elements canbe embedded under the active area 71 to respectively measure and adjustthe pH of the aqueous sample 5. The pH of the aqueous sample in the SPDMcan be adjusted kept constant for analyte analysis, or the pH can becycled to promote certain reactions. Moisture sensors, blood cellcounters and other solid state sensor and actuators can be embeddedunder active area.

Heating elements can be placed under a portion of the active area 71 orunder a portion of sedimentation capillary 13. Heating elements can beplaced under the entire active area 71 or under the entire sedimentationcapillary 13 but only a portion can be activated. Heating elementsembedded under surface 7 of the IC 12 can be used to create eddycurrents or convection currents to mix the magnetic particles insolution. Heating elements under a portion of the sedimentationcapillary 13 can heat fluid in proximity. The rising heated fluid from aportion of the sedimentation capillary can generate eddy currents orconvection currents that keep the magnetic particles in suspension andincubating with the target in the sedimentation capillary. The heatingelements can be enabled before the dry sphere 3 dissolves or after thedry sphere dissolves.

FIG. 10 shows a cross section of the system with delivery capillary 14leading to a first surface capillary 15 and a second surface capillary62. Surface capillary 15 leads to a first sedimentation capillary 13 andsurface capillary 62 leads to a second sedimentation capillary 63. Eachsedimentation capillary can have a different dried sphere at the top.The surface of the sensing areas below each sedimentation capillary canhave different functional chemistry coatings. In this system, multipleassays can be performed simultaneously without mixing between thesedimentation capillaries. The heights of the different sedimentationcapillaries can be different and can be tailored to the incubation timenecessary for the assay being performed in the sedimentation capillary.More than one assay can be performed in one sedimentation capillary.More than two surface capillaries leading to more than two sedimentationcapillaries can be integrated on the same system. The surfacecapillaries can be connected in a star network, an H-network or anyother network of surface capillaries allowing the aqueous sample to flowfrom one or more filters through one or more delivery capillaries toreach one or more sedimentation capillaries.

To minimize the amount of sample and the number of applications, all thesurface capillaries can share the same delivery capillary and the samefilter. One or more sedimentation capillaries can be reservedexclusively for performing assay controls.

To ensuring proper functioning of all assay components, conventionalnon-quantitative immunoassays rely on negative controls using anirrelevant antibody of the same isotype to determine the non-specificsignal or background, and positive controls using anti-speciesantibodies to generate a positive signal.

Quantitative immunoassays rely on calibrators—known quantities ofanalyte (calibrators) in a synthetic matrix—to quantify unknowns.

This fully integrated assay system 10 can use a sample specific internalassay calibration that relies on the sample matrix itself to extrapolatethe background signal and the native target signal.

To calibrate the native target signal resulting from the native targetconcentration in the aqueous sample 5, the assay system can contain twosedimentation capillaries 13 and 63, that may or may not be fluidicallyconnected to the same delivery capillary 14. A pre-determined quantityof a dry calibrant consisting of lyophilized synthetic target or targetderivative, or target analogue, can be added in the dry sphere at thetop of sedimentation capillary 63, along the sides of sedimentationcapillary 63, on the surface 7 of the chip 12 at the bottom ofsedimentation capillary 63, in the surface capillary 62 leading tosedimentation capillary 63, or on the surface 7 of the chip 12 in thesurface capillary 62. The preferred location for the dry calibrant is onthe surface 7 of the chip 12 in the surface capillary 62 since thelyophilized target can be deposited at the same time as the sensing areais being coated, and since it enters into the sedimentation capillary 62in a dissolved state, akin to the native target. The surface capillary62 cannot flow into sedimentation capillary 13 since the dry calibrantwould corrupt the detection of the native target signal. The drycalibrant will be rehydrated by the sample and flow into thesedimentation capillary 63. The quantity of dry calibrant insedimentation capillary 63 can be between 1 zeptogram and 1 attogram,between 1 attogram and 1 femtogram, between 1 femtogram and 1 picogram,between 1 picogram and 1 nanogram or between 1 nanogram and 1 microgram.A different quantity 2 of dry calibrant, or no dry calibrant, can beloaded in the dry sphere at the top of sedimentation capillary 13, alongthe sides of sedimentation capillary 13, on the surface 7 of the chip 12at the bottom of sedimentation capillary 13, in the surface capillary 15leading to sedimentation capillary 13, or on the surface 7 of the chip12 in the surface capillary 15. The difference in signals in the twosedimentation capillaries 13 and 63, i.e. the difference in the numberof specifically bound magnetic particles in sedimentation capillaries 13and 63 can be used to calibrate the native target signal resulting fromthe native target concentration in the sample by a signal calibrationmathematical operation. The signal calibration mathematical operationcan include addition, subtraction, multiplication, division, non-linearcorrelation through look-up tables and can be performed digitally on thechip 12. An arithmetic logic unit can be integrated on the chip 12 toperform the signal calibration mathematical operation. The sedimentationcapillaries 13 and 63 must be positioned to avoid the dry calibrantintended to flow into sedimentation capillary 63 from diffusion ortraveling or flowing to sedimentation capillary 13 and to avoid the drycalibrant intended to flow in sedimentation capillary 13 from diffusionor traveling or flowing to sedimentation capillary 63. The height ofcapillary 63 can be shorter than capillary 13 to minimize the amount ofsample volume needed to calibrate the native target signal.

To calculate the background signal, i.e. the abnormally strongly boundmagnetic particles resulting from undesirable non-specific interactions,the system can contain a first sedimentation capillaries 13 and a thirdsedimentation capillary 64. The sedimentation capillary 64 can have adifferent height than sedimentation capillary 13 resulting in adifferent sedimentation times and by extension incubation time. In sodoing, the number of specifically bound magnetic particles resultingfrom the native target concentration in the sample will be different insedimentation capillary 13 versus sedimentation capillary 64 due to thedifferent incubation times. Meanwhile, the background signal, or thenumber of non-specifically bound magnetic particles will remainapproximately equal. The difference in the number of bound magneticparticles, both specifically and background non-specifically, insedimentation capillaries 13 and 64 can be used to determine the numberof background non-specifically bound magnetic particles by a backgroundcalculation mathematical operation. That background calculationmathematical operation can include addition, subtraction,multiplication, division, non-linear correlation through look-up tablesand can be performed digitally on the chip 12. An arithmetic logic unitcan be integrated on the chip 12 to perform the background calculationmathematical operation.

The native target signal is correlated to the magnetic bead settlingtime, i.e. the incubation time, while the background signal remainsapproximately constant with incubation time. To measure the backgroundsignal, 2 concurrent assays, Assay 1 and Assay 2, can be run in twodifferent sedimentation capillaries with different heights,corresponding to for example 12 and 2 minutes incubation timesrespectively. Assay 1 bead count B1 consists of a background signal Bkgand a native target signal component Sig1: B1=Bkg+Sig1. Similarly, Assay2 bead count B2 consists of the same background signal Bkg but with adifferent native target signal Sig1: B2 Bkg+Sig2, where Sig1 equalsapproximately 6 Sig2 according to the ratio of the incubation times. Thebackground signal and the native target signals can easily be extractedarithmetically: Sig1=(B1−B2)*(6/5), Bkg=B1−Sig1, and Sig2=B2−Bkg. Notethat the two incubation times depend on the heights h1 and h2 of thechambers and their ratio can be controlled tightly by design,irrespective of sample viscosity. The ratio of h1 to h2 can be increasedas much as possible for more precise measurement of the backgroundsignal. The ratio can be between 1:1 and 1.5:1, between 1.5:1 to 2:1,between 2:1 and 4:1, between 4:1 and 8:1, between 8:1 and 16:1, between16:1 and 100:1.

More than 2 sedimentation capillaries can be implemented on the sameassay system 10 to perform native target signal calibration andbackground non-specifically bound magnetic particles calculation fromthe same aqueous sample 5. Three sedimentation capillaries can be usedper analyte. A first sedimentation capillary can be used to perform thestandard assay, a second sedimentation capillary can be used to measurethe background signal, while a predetermined amount of a dry calibrantcan be spiked into the surface capillary leading to a thirdsedimentation capillary, which can be used to calibrate the nativetarget signal.

In a multiplexed format, the sedimentation capillaries can be grouped tominimize the total amount of volume of aqueous sample 5 needed. Multiplebackground signal measurements for multiple analytes can be performedusing the same sedimentation capillaries, while multiple native signalcalibrations for multiple analytes can be performed using the samesedimentation capillaries. Native signal calibration for a first analyteand background measurement for a second analyte can be performed usingthe same sedimentation capillary.

The background signal measurement and native target signal measurementcan also be used qualitatively to invalidate the test for example shouldthey fall outside expected ranges. The background signal measurement andnative target measurement can be performed on more than one targetsconcurrently or in series on the same system or moreover on the samechip.

For qualitative yes/no measurements, the background signal measurementand the native target signal calibration can be performed using a singlesedimentation capillary 63 to minimize the volume of aqueous sample 5needed. In this case, the height of sedimentation capillary 63 can be aratio r of the height of sedimentation capillary 13. Seimentationcapillary 63 can contain the dissolved dry calibrant. The bead counts inthe sedimentation capillaries 13 and 63 is given respective byB1=Sig1+Bkg and B2=Sig2+Bkg+Cal. The difference between the bead countsis given by B1−B2=Sig1+Bkg−Sig2−Bkg−Cal. Sig1 and Sig2 are ratioedaccording to the ratio r of the heights of the sedimentation capillaries13 and 63 and Cal is the solubilized dry calibrant concentration insedimentation capillary 63. B1−B2=Sig1*(1−r)−Cal. The amount of drycalibrant can chosen to be so that the concentration of resolubilizeddry calibrant in sedimentation capillary 63 is equal to a qualitativeconcentration threshold multiplied by (1−r).B1−B2=Sig*(1-r)−Threshold*(1−r). As a results B1>B2 when Sig>Thresholdand B2>B1 when Sig<Threshold.

The bead count to target concentration relationship is non-linear soadditional calculation can be performed when assay system operates inthe non-linear slope of the bead count to concentration curve. The IC 12can perform the non-linear calculation or store a look-up table with therelationship to convert between bead count and target concentration andback. Target concentration refers to native target and calibrantconcentration.

The on-chip generated magnetic separation forces can be adjusted suchthat the background signal is zero beads. In this case, no measurementof the background signal is needed.

FIG. 11 shows a cross section of the integrated circuit 12 mounted ontothe PCB 9 and electrically connected via a wirebond 81. The wirebond 81can be hermetically sealed by encapsulant 80. The SPDM 8 can be placeddirectly on the exposed surface 7 of the IC 12. The encapsulant can bean epoxy, acylate, urethanes, silicones or other adhesives.

FIG. 12 shows a cross section of the integrated circuit 12 mounted ontothe PCB 9 and electrically connected by way of one or more throughsilicon vias 82. The use of through silicon vias which can be placedunder the active sensing area can minimize the area of the IC 12 devotedto pads or input/output functions and by extension minimize the cost ofIC 12. The SPDM 8 can be placed directly on the exposed surface 7 of theIC 12.

FIG. 13 shows the top view of the integrated circuit surface 7 with onededicated magnetic separation conductors 90 for each sensor 20. Eachdedicated magnetic separation conductor can be individually addressedand activated. The current through each dedicated magnetic separationconductor can be precisely set to achieve the desired force on amagnetic particle 24 atop a sensor 26. When a magnetic particle lands ona sensor, it can be detected and the dedicated magnetic separationconductor can be used to remove it if it is non-specifically boundwithout disturbing other magnetic particles more than one sensor lengthaway. The non-specifically bound magnetic particles can be removed oneby one off their corresponding sensors by dedicated separationconductors for superior assay control and precision.

Each sensor can have more than one dedicated magnetic separationconductors. For example, each sensor can have two dedicated magneticseparation conductors, one on each side for bi-lateral magneticseparation. A dedicated magnetic separation conductor can be shared withone or more neighboring sensor.

FIG. 14 shows the top view of the integrated circuit surface 7 with onededicated magnetic concentration conductor 92 for each sensor 20. Eachdedicated magnetic concentration conductor 92 can be individuallyaddressed and activated. The current through each dedicated magneticconcentration conductor can be precisely set to achieve the desiredconcentration force on a magnetic particle sedimenting atop a sensor 20.Magnetic particles can be pulled atop sensors by dedicated magneticconcentration conductor 92, and once the magnetic particle it atop thesensor, the dedicated magnetic concentration conductor can be switchedoff.

Each sensor can have more than one dedicated magnetic concentrationconductors for rastering the magnetic particles. A dedicated magneticconcentration conductor can be shared with one or more neighboringsensor. Rastering is the process of moving or rolling a particle on thesurface 7 of the IC 12 to promote specific binding.

The magnetic particles can be rastered on the surface by the dedicatedconcentration conductors and the dedicated separation conductorsapplying one or more magnetic rastering forces. On the flat X-Y planarsurface 7 of the IC 12, the dedicated separation conductors can bearrayed in rows in the x-direction and the dedicated concentrationconductors can be arrayed in columns in the y-direction. In so doing,non-specifically bound magnetic particles can be rastered2-dimensionally in the positive and negative X and Y directions by arastering algorithm that controls the movement of each particleindividually, or one or more ensembles of particles. The particles canbe rastered by on-chip generated magnetic rastering forces until theyform a binding interaction on the surface 7 of the IC 12, preventing theparticle from rastering further. A detection algorithm can detect when aparticle is no longer rastering on the surface of the IC, and activatethe magnetic separation forces. The magnetic separation forces can beapplied and if the particle is non-specifically bound, the particle canbe removed atop the sensor and continue to be rastered across the array.The magnetic separation force can be higher than the magnetic rasteringforce. The magnetic rastering force can be different from the magneticconcentration force. However, if a particle is specifically bound atopthe sensor, then the sensor can detect the particle and the dedicatedconcentration and dedicated separation conductors for that sensor can bede-activated such that other particles are not pulled atop that sensor.The magnetic concentration forces can be used to pull the magneticparticles atop the sensors, to raster the magnetic particles across thesensor or to raster the magnetic particle on top of the sensor. In thelatter case, the particle is detectable throughout the entire rasterprocess. One or more magnetic concentration conductors can be placeddirectly atop a sensor or laterally spaced to a sensor. The opticalsensors can be arrayed densely to ensure a 100% fill factor so that allthe particles or ensembles of particles on the surface of the chip aredetected.

When the particles 4 are released from dissolution of the dry sphere 3,they can disperse throughout the sedimentation capillary 13 and land onthe surface 7 of the IC 12 at different times. In this scenario, theincubation time on the surface 7 of the IC 12 for a given particle 4 canvary depending on when it landed on the surface 7 of the IC 12. Themagnitude of non-specific interactions can depend on the time theparticle 4 lies on the surface 7 of the IC 12, leading to variability inthe assay. To overcome this variability, a sequence of magneticseparation forces can be initiated at different magnetic separationtimes. The magnetic separation times can be determined dynamically atrun-time or pre-determined and stored in memory. At each magneticseparation time, a sequence of magnetic separation forces can be appliedto remove the non-specifically bound particles away from the sensors.Once the magnetic separation is complete, the sequence of magneticseparation forces can be deactivated until the next magnetic separationtime to allow more particles to settle. The assay protocol can consistof more than one magnetic separation times with different or variableintervals between them. The intervals between magnetic separation timescan vary from 5 seconds to 15 minutes, or from 30 seconds to 10 minutes,or from 1 to 5 minutes. The shorter the interval between magneticseparation times, the shorter the opportunity for the particles to landon the surface and bind specifically. The longer the interval betweenmagnetic separation times, the more chance for abnormally strongnon-specific interactions to form. The sequences of magnetic separationforces applied at each magnetic separation time can be different, forexample in magnetic force magnitude, conductors activated, frequency offorces, length of application of forces, magnetic force profile andalgorithm of activation of conductors.

The number of particles can be detected before and after a sequence ofmagnetic separation forces is applied. The specific particle bindingratio is the ratio of the pre-separation number of magnetic particlesdetected by the sensors before the magnetic separation forces areapplied to the post-separation number of magnetic particles detected bythe sensors after the magnetic separation forces are applied. Thespecific particle binding ratio is a useful indicator of binding sinceit eliminates or mitigates the dependence to the absolute number ofparticles that sedimented on the surface 7 of the IC 12.

The sequences of magnetic separation force can be tailored such thatwhen applied, few magnetic particles—i.e. less than 1, or less than 10,or less than 100, or less than 1000, or less than 10000, or less than1000000—can land on the sensor but rather the sedimenting particles canbe pulled toward the separation conductor before they have theopportunity to land on the surface 7 of the IC 12. This way, thepost-separation number can avoid being corrupted by non-specificallybound particles landing on the sensors during the application of themagnetic separation force.

When a sequence of magnetic separation forces is deactivated, thecurrent through the respective separation conductors can be switched offand the magnetic particles can settle on the sensor indiscriminately,while during the magnetic separation sequence, few magneticparticles—i.e. less than 1, or less than 10, or less than 100, or lessthan 1000, or less than 10000, or less than 1000000—may be able tosediment on a sensor.

More than one sequence of magnetic separation forces generatingseparation forces on different areas of the IC 12 can be applied at thesame magnetic separation times, or at different magnetic separationtimes. Multiple areas of the ICs can perform multiple assaysindependently.

An assay can consist of multiple magnetic sequences of magneticseparation forces initiated at multiple magnetic separation times. Afinal sequence of magnetic separation forces can be using strongermagnetic separation forces or magnetic separation forces for longerduration. A specific particle binding ratio can be calculated for eachmagnetic separation sequence, and the multiple specific binding ratioscan be combined to give a final particle binding ration, which cancorrespond to the target analyte concentration in the aqueous sample 5.

A final particle binding ratio can be calculated by dividing the finalnumber of particles detected by the total number of particles thatsedimented onto the sensors. The total number of particles thatsedimented onto the sensor is not straight-forward to calculate if priormagnetic separation sequences were applied before the final magneticseparation sequence. The total number of particles is equal to the sumof all the pre-separation particles counts minus the sum of all thepost-separation particle counts plus the final post-separation particlecount.

The sequence of magnetic separation forces can include a magnetic forcechirp, where the magnetic forces applied can be toggled between the leftand right side of a sensor at increasing frequency. At the beginning ofthe magnetic chirp, strong separation forces strongly remove thenon-specifically bound beads, while at the end of the magnetic chirp,the toggle frequency is too high for the particles to move away from theseparation conductors. This prevents distant separation conductors fromrastering non-specifically bound particles across sensors prior todetection.

The assay system 10 can provide different assay results at differenttimes. Intermediate results can be provided ahead of final results. Theintermediate results can include assay progress information andqualitative assay results before the final quantitative results arecomplete and displayed or transmitted. The intermediate results canprovide expedited qualitative information.

The intermediate results of the assay after each intermediate sequenceof magnetic separation forces can be displayed or transmitted forreal-time updates. In this case, after each intermediate sequence ofmagnetic separation forces, the particle binding ratio can bearithmetically processed is if it were a final sequence of magneticforces.

To expedite access to assay information, expedited qualitative resultsof the assay can be displayed or transmitted before the full assay iscomplete and before precise quantitative information is available. Therelative particle binding ratio at the end of the first magneticseparation interval or any subsequent magnetic separation interval canbe used to provide the expedited qualitative information.

An example of an on-chip assay protocol is given below:

1. IC 12 in standby until detection of aqueous sample on surface of ICunder surface capillary. Once detected, IC 12 activates the heatingelements to heat the aqueous sample to 37C and proceed with protocol.2. IC 12 waits until detect of aqueous sample on surface of IC 12 undersedimentation capillary 13. IC 12 proceeds with protocol when detectedor send error message if timed out.3. IC 12 detects dissolution of dry sphere by changes in light onsensing area 21.4. IC 12 activates magnetic concentration conductors.5. IC 12 waits 2 minutes.6. IC 12 reads out each sensor and counts the pre-separation number ofparticles to give Count 1.7. IC 12 de-activates magnetic concentration conductors.8. IC 12 activates the first sequence of magnetic separation forces toremove all the non-specifically bound particles from the sensorsurfaces.9. IC 12 reads out each sensor and counts the post-separation number ofparticles to give Count 2.10. IC 12 calculated ratio of Count 2/Count 1 and correlates ratio to aconcentration.11. IC 12 displays the concentration or the qualitative information.

Protocol elements 4-10 can be repeated until all the particles havesettled onto the surface of the chip. In each repeat of protocolelements 4-10, the magnetic concentration forces and separation forcescan be varied. A Cumulative Pre-Counts and a Cumulative Post-Count canbe the sum of all the pre-separation counts and all the post-separationcounts, respectively. The different pre-separation counts andpost-separation counts from each sequence of magnetic separation forcescan be combined arithmetically to give a final particle count and afinal binding ratio. In protocol element 11, the correlation functionthat translates the final particle count or final binding ratio to aconcentration of target analyte can be stored on chip from valuesobtained during manufacturing. The correlation function can also includethe results from the background measurement and the native target signalcalibration. The assay can be initiated by the humidity or moisturesensors, or the assay can be initiated by a button or a touch screenintegrated in the assay system 10.

When detecting a particle, the optical sensors can internally performcorrelated double sampling to a calibration value acquired duringmanufacturing, or to a value obtained in real time running the assay.The optical sensor can measure the optical signal before and after aparticle lands on the sensor. The difference or the ratio can becompared to a threshold to determine whether a particle is present. Thesensor can detect the optical signal before and after magneticseparation to detect the removal of a particle.

FIG. 15 shows the cross section of the sedimentation capillary 13 with anotch 100 to prevent the dried sphere 3 falling into the sedimentationcapillary 13. The dried sphere 3 can have smaller diameter than thesedimentation capillary 13 but can be large enough to be prevented bythe notch 100 from falling into the sedimentation capillary.

FIG. 16 shows a cross section of the delivery capillary 14, the surfacecapillary 15 and the sedimentation capillary 13 atop the IC 12. When asmall volume of aqueous sample 5 is applied (i.e. less than 200 ul, orless than 100 ul, or less than 50 ul or less than 30 ul or less than 20ul, or less than 10 ul, or less than 5 ul, or less than 2 ul or lessthan 1 ul), the evaporation of the aqueous sample 5 can results in smallfluidic flows that can disturb the assay on the surface 7 of the chip12. To reduce or eliminate evaporation through the top of thesedimentation capillary 13, the cover 50 can be made or a material thatreduces or eliminates evaporation. Moreover, the air opening 51 can besmall enough in cross section to limit by diffusion or other effects theamount of aqueous sample 5 that can evaporate through it.

A second source of evaporation can occur through the filter 6. In thiscase a “suck-back” pressure (vacuum) can be generated as the aqueoussample evaporates from the filter surface. The filter has a largesurface area and can evaporate fluid at a high rate. When a small amountof sample is applied, the aqueous sample 5 can traverse the filter intothe delivery capillary 14, into the surface capillary 15 and into thesedimentation capillary 13, but can be sucked back through the filterdue to evaporation before the full assay can be performed. This can beovercome by a lid that can close over the sample port on assay system 10after the aqueous sample 5 has been applied and eliminate or reduce theamount of aqueous sample 5 that evaporates into the surroundingenvironment.

Another way of mitigating the evaporation through the top of the filter6 is to implement a passive unidirectional valve in the filter 6, or inthe delivery capillary 14, or in the surface capillary 15, or in thesedimentation capillary 13 or at the top of the sedimentation capillary13 or at the top of the cuvette 30. The passive unidirectional valve canallow the fluid to flow from the filter 6 to the delivery capillary 14,or to the surface capillary 15, or to the sedimentation capillary 13, orto the top of the sedimentation capillary 13 or to the top of thecuvette 30 but not in the reverse direction. The passive unidirectionalvalve can eliminate or reduce the “suck-back” flow resulting fromaqueous sample evaporation through the filter 6.

For ease of use of the assay system 10, a passive unidirectional valverather than an actuated unidirectional valve is desirable. A Martin vent110 is a passive unidirectional valve that can relieve the “suck-back”pressure with air. The Martin vent 110 provides a low impedance path forair to be sucked back towards the filter without passing through thesedimentation capillary 13, thereby leaving the fluid in thesedimentation capillary 13 intact and the assay able to completeunmolested. To prevent the aqueous sample 5 from leaking out of theMartin vent, a microfluidic stop gap 112 or fluid trap can beimplemented at the terminus of the Martin vent 110. The design of thismicrofluidic stop gap can be such that its surface tension in thedirection of the filter is less than the surface tension in thesedimentation capillary or in the cuvette in the direction of the filtersuch that air will preferentially flow from the Martin vent as opposedto the cuvette or sedimentation capillary.

The Martin vent can be placed anywhere along the length of the deliverycapillary or surface capillary that prevents a “suck-back” pressurebeing generated by the filter when the fluid in the filter begins toevaporate from pulling or sucking back the fluid in the SPDM.Alternatively, a microfluidic check valve may be placed anywhere betweenthe outlet of the filter and the sedimentation capillary.

FIG. 17A and B present cross sectional side views of a passiveunidirectional valve that can seal the sedimentation capillary 13 oncethe aqueous sample dissolves the dry sphere 3 by blocking the flow ofair or fluid through the top of the sedimentation capillary 13. A flowstop 120 can be placed above the dry sphere 3. While the dry sphere 3remains dry, the flow stop 120 cannot seal the sedimentation capillary 3and can allow air and fluid to move through the top of the sedimentationcapillary 13 (FIG. 17A). Once the dry sphere 3 dissolves, the flow stop120 can drop down vertically or through other mechanism seal the top ofthe sedimentation capillary (FIG. 17B) and prevent or impede air orother fluid flowing through the top of the sedimentation capillary 13.

The flow stop 120 can be any shape that creates a hermetic seal or highimpedance seal with the top of the sedimentation capillary 13 or tocreate a hermetic seal or high impedance inside the sedimentationcapillary 13. For example, the flow stop 120 can fit flush with the topor inner sidewall of the sedimentation capillary 13. The flow stop 120can be shaped to allow a small amount of air or fluid through. The flowstop 120 can use the surface tension from a vapor seal to seal the topof the sedimentation capillary 13.

The flow stop 120 can be sized such that is cannot tilt or move insidethe cuvette or the sedimentation capillary 13 before the dry spheredissolves. It can be light-weight such that the weight of flow stop 120does not crush the dry sphere 3 during use, in manufacturing ortransportation. The flow stop 120 can be transparent or translucent toallow light to pass through it into the sedimentation capillary 13.

Another example of a passive unidirectional valve is an air opening 51.The air opening 51 can be a small diameter capillary or small diameteropening (i.e. less than 1 mm, or less than 0.1 mm, or less than 0.01 mm,or less than 1 um, or less than 1 nm) and can be placed at the top ofthe sedimentation capillary 13 or at the top of the cuvette 30 or in thecover 50. The air opening 51 can allow the air or aqueous fluid throughbut will not allow the aqueous fluid back out. The air opening 51 canblock the fluid from exiting by capillary force if the effectivediameter of the air opening 51 is small enough. The air opening 51 canbe coated with a material that reacts with the aqueous sample toconstrict the air opening 51 or seal it altogether

The surface 7 of the chip 9 can be coated with a thin opticallytransparent reagent adhesion layer. The protein adhesion layer canconsist of gold, silver, chrome, polymer, silicon dioxide, polyimide orsilicon nitride. The reagent adhesion layer can be thermally deposited,chemically deposited or spun on, or other method. The reagent adhesionlayer can be less than 50 nm or less than 25 nm or less than 20 nm orless than 15 nm or less than 10 nm or less than 5 nm or less than 3 nmor less than 1 nm. For proper adhesion to silicon or silicon dioxide ofthe reagent adhesion layer, an additional adhesion layer of chromium ortitanium can be used. The additional adhesion layer can be opticallytransparent and can be less than 50 nm or less than 25 nm or less than20 nm or less than 15 nm or less than 10 nm or less than 5 nm or lessthan 3 nm or less than 1 nm. The reagent adhesion layer can be coatedwith streptavidin by passive adsorption. Biotinylated anti-bodies can bebound to the streptavidin. The reagent adhesion layer can be depositedover the entire chip, or the sensing area or localized on the individualsensors. The reagent adhesion layer can be deposited after the IC hasbeen assembled onto the PCB to eliminate any contamination that occurredduring the manufacturing process.

To minimize power dissipation and heat generation, the separationconductors can be implemented in thick top metal (top metallizationhaving a deposition thickness greater than 1 um, or greater than 2 um orgreater than 3 um). To eliminate the topology from the thick top metalcan affect the assay performance, the surface can be chemicallymechanically polished (CMPed). Openings in the top metal forilluminating the optical sensors below can be used to collimate thelight for improved detection SNR. The increased thickness of the topmetal could increase the SNR despite the increased distance from theparticle to the optical sensor.

The platform described herein can be used for applications including,but not limited to, diagnostics such as simplex assays, parallel ormultiplexed assays, DNA micro-array assays, glucose, cholesterol,metabolites, and small molecules detection; environmental assays such asfor food contamination, and water and/or soil contamination; proteomicssuch as protein-protein binding force measurements, protein-proteinbinding resonant frequencies, protein kinetics research; genomics suchas DNA methylation profile, and DNA force measurements; magneticparticle 4 atomic force microscopy (AFM) such as low 1/f noise AFM, AFMwith digitally controlled force and frequency, and multiplexed AFM;Magnetic Particle Characterization such as exploration of magneticproperties of particles of different sizes and characteristics; Low CostBio-sensor Networks such as integrated and direct wireless transmissionof assay results, and real-time outbreak and/or contaminationmonitoring; and any combinations thereof.

Variations of the systems, devices and methods have been shown anddescribed herein by way of example only. Variations, changes, andsubstitutions can occur. For example, the methods can be performed withany one or more elements of the methods absent, and any one or moreelement of the devices can be omitted. Various alternatives andcombinations of elements between the variations described herein may beemployed. All publications, patents, and patent applications mentionedin this specification are herein incorporated by reference to the sameextent as if each individual publication, patent, or patent applicationwas specifically and individually indicated to be incorporated byreference.

1. (canceled)
 2. An assay system for generating presentable assayinformation from an aqueous solution, comprising: a filter; a surfacecapillary; a delivery capillary, wherein the delivery capillary fluidlyconnects the filter to the surface capillary; a sedimentation capillary,wherein the surface capillary fluidly connects the delivery capillary tothe sedimentation capillary; a dry sphere placed at the top of thesedimentation capillary, wherein the dry sphere contains magneticparticles, wherein the dry sphere is held motionless within a cuvettehaving vertical side walls, wherein the cuvette is configured to holdthe aqueous solution and the dry sphere simultaneously; an integratedcircuit placed below the sedimentation capillary; magnetic particlesensors embedded in the integrated circuit at the bottom of thesedimentation capillary, wherein the magnetic particle sensors arecapable of detecting magnetic particles specifically bound to a surfaceof the integrated circuit; and a display for displaying presentableassay information.
 3. The system of claim 2, wherein the cuvettecomprises a flow stop placed above the dry sphere, wherein the flow stopseals the sedimentation capillary when the dry sphere dissolves.
 4. Thesystem of claim 2, wherein a passive unidirectional valve is configuredto eliminate and/or reduce the suck-back flow resulting from aqueoussample evaporation through the filter.
 5. The system of claim 2, whereina magnetic particle sensor is configured to detect a single specificmolecular interaction between the surface of the integrated circuit anda magnetic particle.
 6. The system of claim 5, wherein an array ofmagnetic particle sensors is configured to count the number of specificmolecular interactions in a sensing area on the surface of theintegrated circuit.
 7. The system of claim 2, wherein the sedimentationcapillary comprises a notch, wherein the notch is configured to preventthe dry sphere from failing into the sedimentation capillary.
 8. Thesystem of claim 2, wherein the cuvette comprises tapered sidewalls,wherein the tapered sidewalls are configured to hold the dry sphere inplace within the sedimentation capillary.
 9. A method of generatingpresentable assay information from an aqueous solution, comprising:passing the aqueous sample through a filter into a delivery capillary;delivering the aqueous sample from the delivery capillary to a surfacecapillary and from the surface capillary to a sedimentation capillary;detecting the presence of a target analyte in the aqueous sample byintroducing the aqueous sample to reacting magnetic particles within adry sphere, the dry sphere being placed within a cuvette fluidlyconnected to the sedimentation capillary, the cuvette having verticalside walls, wherein the cuvette is configured to hold the aqueous sampleand the dry sphere simultaneously; dissolving the dry sphere with theaqueous sample such that the reacting magnetic particles release andsediment to a surface of an integrated circuit; attracting the magneticparticles to bind on the surface of the integrated circuit usingmagnetic concentration conductors within the integrated circuit;quantifying the concentration of the target analyte within the aqueoussolution with magnetic particle sensors embedded in the integratedcircuit, wherein the magnetic particle sensors are capable of detectingthe magnetic particles specifically bound to the surface of theintegrated circuit; and displaying the information of the aqueoussolution on a digital display.
 10. The method of claim 9, furthercomprising placing a flow stop above the dry sphere in the cuvette,wherein the flow stop seals the sedimentation capillary when the drysphere dissolves.
 11. The method of claim 9, further comprising apassive unidirectional valve that eliminates and/or reduces thesuck-back flow resulting from aqueous sample evaporation through thefilter.
 12. The method of claim 9, wherein an array of magnetic particlesensors is configured to count the number of specific molecularinteractions in a sensing area on the surface of the integrated circuit.13. The method of claim 9, further comprising providing thesedimentation capillary with a notch that prevents the dry sphere fromfailing into the sedimentation capillary.
 14. The method of claim 9,wherein the cuvette comprises tapered sidewalls, wherein the taperedsidewalls hold the dry sphere in place within the sedimentationcapillary.
 15. The method of claim 9, further comprising illuminatingthe surface of the integrated circuit with a plurality of light sources,wherein the plurality of light sources are configured to identifymagnetic particles dyed with different colors.
 16. The method of claim15, wherein the magnetic particle sensors comprise optical sensors,wherein the optical sensors are configured to identify the color of amagnetic particle.
 17. An assay system for generating presentable assayinformation from an aqueous sample, comprising: a filter; a capillarysystem, wherein the capillary system has a delivery capillary, a surfacecapillary, and a sedimentation capillary, wherein the deliverycapillary, the surface capillary, and the sedimentation capillary arefluidly connected; a dry sphere containing magnetic particles therein;and a cuvette extending from the sedimentation capillary, wherein thecuvette has vertical side walls, and wherein the cuvette is configuredto hold the dry sphere motionless in place.
 18. The system of claim 17,wherein the cuvette comprises tapered sidewalls, wherein the taperedsidewalls are configured to hold the dry sphere in place within thesedimentation capillary.
 19. The system of claim 17, wherein thesedimentation capillary comprises a notch, wherein the notch isconfigured to prevent the dry sphere from falling into the sedimentationcapillary.
 20. The system of claim 17, wherein the cuvette comprises aflow stop placed above the dry sphere, wherein the flow stop isconfigured to seal the sedimentation capillary upon dissolution of thedry sphere.
 21. The system of claim 17, wherein a passive unidirectionalvalve is configured to eliminate and/or reduce the suck-back flowresulting from aqueous sample evaporation through the filter.